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more tutorial work

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add fixed_timestep command-line parameter, 0 means disabled (variable timestep)
This commit is contained in:
erwincoumans
2015-08-07 14:18:57 -07:00
parent 89c2a729ce
commit de4dcdbb18
6 changed files with 555 additions and 3 deletions
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533
examples/Tutorial/Dof6ConstraintTutorial.cpp Normal file
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#include "Dof6ConstraintTutorial.h"
#include "btBulletDynamicsCommon.h"
#include "BulletDynamics/ConstraintSolver/btNNCGConstraintSolver.h"
#include "BulletDynamics/MLCPSolvers/btMLCPSolver.h"
#include "BulletDynamics/MLCPSolvers/btSolveProjectedGaussSeidel.h"
#include "BulletDynamics/MLCPSolvers/btLemkeSolver.h"
#include "BulletDynamics/MLCPSolvers/btDantzigSolver.h"
#include "../RenderingExamples/TimeSeriesCanvas.h"
#include "BulletDynamics/ConstraintSolver/btGeneric6DofSpring2Constraint.h"
#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif
#ifndef M_PI_2
#define M_PI_2 1.57079632679489661923
#endif
#ifndef M_PI_4
#define M_PI_4 0.785398163397448309616
#endif
extern float g_additionalBodyMass;
//comment this out to compare with original spring constraint
#define USE_6DOF2
#ifdef USE_6DOF2
#define CONSTRAINT_TYPE btGeneric6DofSpring2Constraint
#define EXTRAPARAMS
#else
#define CONSTRAINT_TYPE btGeneric6DofSpringConstraint
#define EXTRAPARAMS ,true
#endif
#include "../CommonInterfaces/CommonRigidBodyBase.h"
struct Dof6ConstraintTutorial : public CommonRigidBodyBase
{
struct Dof6ConstraintTutorialInternalData* m_data;
Dof6ConstraintTutorial(struct GUIHelperInterface* helper);
virtual ~Dof6ConstraintTutorial();
virtual void initPhysics();
virtual void stepSimulation(float deltaTime);
void animate();
virtual void resetCamera()
{
float dist = 5;
float pitch = 722;
float yaw = 35;
float targetPos[3]={4,2,-11};
m_guiHelper->resetCamera(dist,pitch,yaw,targetPos[0],targetPos[1],targetPos[2]);
}
};
struct Dof6ConstraintTutorialInternalData
{
btRigidBody* m_TranslateSpringBody;
btRigidBody* m_TranslateSpringBody2;
btRigidBody* m_RotateSpringBody;
btRigidBody* m_RotateSpringBody2;
btRigidBody* m_BouncingTranslateBody;
btRigidBody* m_MotorBody;
btRigidBody* m_ServoMotorBody;
btRigidBody* m_ChainLeftBody;
btRigidBody* m_ChainRightBody;
CONSTRAINT_TYPE* m_ServoMotorConstraint;
CONSTRAINT_TYPE* m_ChainLeftConstraint;
CONSTRAINT_TYPE* m_ChainRightConstraint;
TimeSeriesCanvas* m_timeSeriesCanvas;
float mDt;
unsigned int frameID;
Dof6ConstraintTutorialInternalData()
: mDt(1./60.),frameID(0)
{
}
};
Dof6ConstraintTutorial::Dof6ConstraintTutorial(struct GUIHelperInterface* helper)
:CommonRigidBodyBase(helper)
{
m_data = new Dof6ConstraintTutorialInternalData;
m_data->m_timeSeriesCanvas = new TimeSeriesCanvas(helper->get2dCanvasInterface(),256,256,"Position and Velocity");
m_data->m_timeSeriesCanvas ->setupTimeSeries(20,100, 0);
m_data->m_timeSeriesCanvas->addDataSource("X position (m)", 255,0,0);
m_data->m_timeSeriesCanvas->addDataSource("X velocity (m/s)", 0,0,255);
m_data->m_timeSeriesCanvas->addDataSource("dX/dt (m/s)", 0,0,0);
}
Dof6ConstraintTutorial::~Dof6ConstraintTutorial()
{
delete m_data->m_timeSeriesCanvas;
m_data->m_timeSeriesCanvas = 0;
exitPhysics();
delete m_data;
}
void Dof6ConstraintTutorial::initPhysics()
{
// Setup the basic world
m_guiHelper->setUpAxis(1);
m_collisionConfiguration = new btDefaultCollisionConfiguration();
m_dispatcher = new btCollisionDispatcher(m_collisionConfiguration);
btVector3 worldAabbMin(-10000,-10000,-10000);
btVector3 worldAabbMax(10000,10000,10000);
m_broadphase = new btAxisSweep3 (worldAabbMin, worldAabbMax);
/////// uncomment the corresponding line to test a solver.
//m_solver = new btSequentialImpulseConstraintSolver;
m_solver = new btNNCGConstraintSolver;
//m_solver = new btMLCPSolver(new btSolveProjectedGaussSeidel());
//m_solver = new btMLCPSolver(new btDantzigSolver());
//m_solver = new btMLCPSolver(new btLemkeSolver());
m_dynamicsWorld = new btDiscreteDynamicsWorld(m_dispatcher,m_broadphase,m_solver,m_collisionConfiguration);
m_dynamicsWorld->getDispatchInfo().m_useContinuous = true;
m_guiHelper->createPhysicsDebugDrawer(m_dynamicsWorld);
m_dynamicsWorld->setGravity(btVector3(0,0,0));
// Setup a big ground box
{
btCollisionShape* groundShape = new btBoxShape(btVector3(btScalar(200.),btScalar(5.),btScalar(200.)));
btTransform groundTransform;
groundTransform.setIdentity();
groundTransform.setOrigin(btVector3(0,-10,0));
#define CREATE_GROUND_COLLISION_OBJECT 1
#ifdef CREATE_GROUND_COLLISION_OBJECT
btCollisionObject* fixedGround = new btCollisionObject();
fixedGround->setCollisionShape(groundShape);
fixedGround->setWorldTransform(groundTransform);
m_dynamicsWorld->addCollisionObject(fixedGround);
#else
localCreateRigidBody(btScalar(0.),groundTransform,groundShape);
#endif //CREATE_GROUND_COLLISION_OBJECT
}
m_dynamicsWorld->getSolverInfo().m_numIterations = 100;
btCollisionShape* shape;
btVector3 localInertia(0,0,0);
btDefaultMotionState* motionState;
btTransform bodyTransform;
btScalar mass;
btTransform localA;
btTransform localB;
CONSTRAINT_TYPE* constraint;
//static body centered in the origo
mass = 0.0;
shape= new btBoxShape(btVector3(0.5,0.5,0.5));
localInertia = btVector3(0,0,0);
bodyTransform.setIdentity();
motionState = new btDefaultMotionState(bodyTransform);
btRigidBody* staticBody = new btRigidBody(mass,motionState,shape,localInertia);
m_dynamicsWorld->addRigidBody(staticBody);
/////////// box with undamped translate spring attached to static body
/////////// the box should oscillate left-to-right forever
{
mass = 1.0;
shape= new btBoxShape(btVector3(0.5,0.5,0.5));
shape->calculateLocalInertia(mass,localInertia);
bodyTransform.setIdentity();
bodyTransform.setOrigin(btVector3(-2,0,-5));
motionState = new btDefaultMotionState(bodyTransform);
m_data->m_TranslateSpringBody = new btRigidBody(mass,motionState,shape,localInertia);
m_data->m_TranslateSpringBody->setActivationState(DISABLE_DEACTIVATION);
m_dynamicsWorld->addRigidBody(m_data->m_TranslateSpringBody);
localA.setIdentity();localA.getOrigin() = btVector3(0,0,-5);
localB.setIdentity();
constraint = new CONSTRAINT_TYPE(*staticBody, *m_data->m_TranslateSpringBody, localA, localB EXTRAPARAMS);
constraint->setLimit(0, 1,-1);
constraint->setLimit(1, 0, 0);
constraint->setLimit(2, 0, 0);
constraint->setLimit(3, 0, 0);
constraint->setLimit(4, 0, 0);
constraint->setLimit(5, 0, 0);
constraint->enableSpring(0, true);
constraint->setStiffness(0, 100);
#ifdef USE_6DOF2
constraint->setDamping(0, 0);
#else
constraint->setDamping(0, 1);
#endif
constraint->setEquilibriumPoint(0, 0);
constraint->setDbgDrawSize(btScalar(2.f));
m_dynamicsWorld->addConstraint(constraint, true);
}
#if 0
/////////// box with rotate spring, attached to static body
/////////// box should swing (rotate) left-to-right forever
{
mass = 1.0;
shape= new btBoxShape(btVector3(0.5,0.5,0.5));
shape->calculateLocalInertia(mass,localInertia);
bodyTransform.setIdentity();
bodyTransform.getBasis().setEulerZYX(0,0,M_PI_2);
motionState = new btDefaultMotionState(bodyTransform);
m_data->m_RotateSpringBody = new btRigidBody(mass,motionState,shape,localInertia);
m_data->m_RotateSpringBody->setActivationState(DISABLE_DEACTIVATION);
m_dynamicsWorld->addRigidBody(m_data->m_RotateSpringBody);
localA.setIdentity();localA.getOrigin() = btVector3(0,0,0);
localB.setIdentity();localB.setOrigin(btVector3(0,0.5,0));
constraint = new CONSTRAINT_TYPE(*staticBody, *m_data->m_RotateSpringBody, localA, localB EXTRAPARAMS);
constraint->setLimit(0, 0, 0);
constraint->setLimit(1, 0, 0);
constraint->setLimit(2, 0, 0);
constraint->setLimit(3, 0, 0);
constraint->setLimit(4, 0, 0);
constraint->setLimit(5, 1, -1);
constraint->enableSpring(5, true);
constraint->setStiffness(5, 100);
#ifdef USE_6DOF2
constraint->setDamping(5, 0);
#else
constraint->setDamping(5, 1);
#endif
constraint->setEquilibriumPoint(0, 0);
constraint->setDbgDrawSize(btScalar(2.f));
m_dynamicsWorld->addConstraint(constraint, true);
}
/////////// box with bouncing constraint, translation is bounced at the positive x limit, but not at the negative limit
/////////// bouncing can not be set independently at low and high limits, so two constraints will be created: one that defines the low (non bouncing) limit, and one that defines the high (bouncing) limit
/////////// the box should move to the left (as an impulse will be applied to it periodically) until it reaches its limit, then bounce back
{
mass = 1.0;
shape= new btBoxShape(btVector3(0.5,0.5,0.5));
shape->calculateLocalInertia(mass,localInertia);
bodyTransform.setIdentity();
bodyTransform.setOrigin(btVector3(0,0,-3));
motionState = new btDefaultMotionState(bodyTransform);
m_data->m_BouncingTranslateBody = new btRigidBody(mass,motionState,shape,localInertia);
m_data->m_BouncingTranslateBody->setActivationState(DISABLE_DEACTIVATION);
m_data->m_BouncingTranslateBody->setDeactivationTime(btScalar(20000000));
m_dynamicsWorld->addRigidBody(m_data->m_BouncingTranslateBody);
localA.setIdentity();localA.getOrigin() = btVector3(0,0,0);
localB.setIdentity();
constraint = new CONSTRAINT_TYPE(*staticBody, *m_data->m_BouncingTranslateBody, localA, localB EXTRAPARAMS);
constraint->setLimit(0, -2, SIMD_INFINITY);
constraint->setLimit(1, 0, 0);
constraint->setLimit(2, -3, -3);
constraint->setLimit(3, 0, 0);
constraint->setLimit(4, 0, 0);
constraint->setLimit(5, 0, 0);
#ifdef USE_6DOF2
constraint->setBounce(0,0);
#else //bounce is named restitution in 6dofspring, but not implemented for translational limit motor, so the following line has no effect
constraint->getTranslationalLimitMotor()->m_restitution = 0.0;
#endif
constraint->setParam(BT_CONSTRAINT_STOP_ERP,0.995,0);
constraint->setParam(BT_CONSTRAINT_STOP_CFM,0.0,0);
constraint->setDbgDrawSize(btScalar(2.f));
m_dynamicsWorld->addConstraint(constraint, true);
constraint = new CONSTRAINT_TYPE(*staticBody, *m_data->m_BouncingTranslateBody, localA, localB EXTRAPARAMS);
constraint->setLimit(0, -SIMD_INFINITY, 2);
constraint->setLimit(1, 0, 0);
constraint->setLimit(2, -3, -3);
constraint->setLimit(3, 0, 0);
constraint->setLimit(4, 0, 0);
constraint->setLimit(5, 0, 0);
#ifdef USE_6DOF2
constraint->setBounce(0,1);
#else //bounce is named restitution in 6dofspring, but not implemented for translational limit motor, so the following line has no effect
constraint->getTranslationalLimitMotor()->m_restitution = 1.0;
#endif
constraint->setParam(BT_CONSTRAINT_STOP_ERP,0.995,0);
constraint->setParam(BT_CONSTRAINT_STOP_CFM,0.0,0);
constraint->setDbgDrawSize(btScalar(2.f));
m_dynamicsWorld->addConstraint(constraint, true);
}
/////////// box with rotational motor, attached to static body
/////////// the box should rotate around the y axis
{
mass = 1.0;
shape= new btBoxShape(btVector3(0.5,0.5,0.5));
shape->calculateLocalInertia(mass,localInertia);
bodyTransform.setIdentity();
bodyTransform.setOrigin(btVector3(4,0,0));
motionState = new btDefaultMotionState(bodyTransform);
m_data->m_MotorBody = new btRigidBody(mass,motionState,shape,localInertia);
m_data->m_MotorBody->setActivationState(DISABLE_DEACTIVATION);
m_dynamicsWorld->addRigidBody(m_data->m_MotorBody);
localA.setIdentity();localA.getOrigin() = btVector3(4,0,0);
localB.setIdentity();
constraint = new CONSTRAINT_TYPE(*staticBody, *m_data->m_MotorBody, localA, localB EXTRAPARAMS);
constraint->setLimit(0, 0, 0);
constraint->setLimit(1, 0, 0);
constraint->setLimit(2, 0, 0);
constraint->setLimit(3, 0, 0);
constraint->setLimit(4, 0, 0);
constraint->setLimit(5, 1,-1);
#ifdef USE_6DOF2
constraint->enableMotor(5,true);
constraint->setTargetVelocity(5,3.f);
constraint->setMaxMotorForce(5,10.f);
#else
constraint->getRotationalLimitMotor(2)->m_enableMotor = true;
constraint->getRotationalLimitMotor(2)->m_targetVelocity = 3.f;
constraint->getRotationalLimitMotor(2)->m_maxMotorForce = 10;
#endif
constraint->setDbgDrawSize(btScalar(2.f));
m_dynamicsWorld->addConstraint(constraint, true);
}
/////////// box with rotational servo motor, attached to static body
/////////// the box should rotate around the y axis until it reaches its target
/////////// the target will be negated periodically
{
mass = 1.0;
shape= new btBoxShape(btVector3(0.5,0.5,0.5));
shape->calculateLocalInertia(mass,localInertia);
bodyTransform.setIdentity();
bodyTransform.setOrigin(btVector3(7,0,0));
motionState = new btDefaultMotionState(bodyTransform);
m_data->m_ServoMotorBody = new btRigidBody(mass,motionState,shape,localInertia);
m_data->m_ServoMotorBody->setActivationState(DISABLE_DEACTIVATION);
m_dynamicsWorld->addRigidBody(m_data->m_ServoMotorBody);
localA.setIdentity();localA.getOrigin() = btVector3(7,0,0);
localB.setIdentity();
constraint = new CONSTRAINT_TYPE(*staticBody, *m_data->m_ServoMotorBody, localA, localB EXTRAPARAMS);
constraint->setLimit(0, 0, 0);
constraint->setLimit(1, 0, 0);
constraint->setLimit(2, 0, 0);
constraint->setLimit(3, 0, 0);
constraint->setLimit(4, 0, 0);
constraint->setLimit(5, 1,-1);
#ifdef USE_6DOF2
constraint->enableMotor(5,true);
constraint->setTargetVelocity(5,3.f);
constraint->setMaxMotorForce(5,10.f);
constraint->setServo(5,true);
constraint->setServoTarget(5, M_PI_2);
#else
constraint->getRotationalLimitMotor(2)->m_enableMotor = true;
constraint->getRotationalLimitMotor(2)->m_targetVelocity = 3.f;
constraint->getRotationalLimitMotor(2)->m_maxMotorForce = 10;
//servo motor is not implemented in 6dofspring constraint
#endif
constraint->setDbgDrawSize(btScalar(2.f));
m_dynamicsWorld->addConstraint(constraint, true);
m_data->m_ServoMotorConstraint = constraint;
}
////////// chain of boxes linked together with fully limited rotational and translational constraints
////////// the chain will be pulled to the left and to the right periodically. They should strictly stick together.
{
btScalar limitConstraintStrength = 0.6;
int bodycount = 10;
btRigidBody* prevBody = 0;
for(int i = 0; i < bodycount; ++i)
{
mass = 1.0;
shape= new btBoxShape(btVector3(0.5,0.5,0.5));
shape->calculateLocalInertia(mass,localInertia);
bodyTransform.setIdentity();
bodyTransform.setOrigin(btVector3(- i,0,3));
motionState = new btDefaultMotionState(bodyTransform);
btRigidBody* body = new btRigidBody(mass,motionState,shape,localInertia);
body->setActivationState(DISABLE_DEACTIVATION);
m_dynamicsWorld->addRigidBody(body);
if(prevBody != 0)
{
localB.setIdentity();
localB.setOrigin(btVector3(0.5,0,0));
btTransform localA;
localA.setIdentity();
localA.setOrigin(btVector3(-0.5,0,0));
CONSTRAINT_TYPE* constraint = new CONSTRAINT_TYPE(*prevBody, *body, localA, localB EXTRAPARAMS);
constraint->setLimit(0, -0.01, 0.01);
constraint->setLimit(1, 0, 0);
constraint->setLimit(2, 0, 0);
constraint->setLimit(3, 0, 0);
constraint->setLimit(4, 0, 0);
constraint->setLimit(5, 0, 0);
for(int a = 0; a < 6; ++a)
{
constraint->setParam(BT_CONSTRAINT_STOP_ERP,0.9,a);
constraint->setParam(BT_CONSTRAINT_STOP_CFM,0.0,a);
}
constraint->setDbgDrawSize(btScalar(1.f));
m_dynamicsWorld->addConstraint(constraint, true);
if(i < bodycount - 1)
{
localA.setIdentity();localA.getOrigin() = btVector3(0,0,3);
localB.setIdentity();
CONSTRAINT_TYPE* constraintZY = new CONSTRAINT_TYPE(*staticBody, *body, localA, localB EXTRAPARAMS);
constraintZY->setLimit(0, 1, -1);
constraintZY->setDbgDrawSize(btScalar(1.f));
m_dynamicsWorld->addConstraint(constraintZY, true);
}
}
else
{
localA.setIdentity();localA.getOrigin() = btVector3(bodycount,0,3);
localB.setIdentity();
localB.setOrigin(btVector3(0,0,0));
m_data->m_ChainLeftBody = body;
m_data->m_ChainLeftConstraint = new CONSTRAINT_TYPE(*staticBody, *body, localA, localB EXTRAPARAMS);
m_data->m_ChainLeftConstraint->setLimit(3,0,0);
m_data->m_ChainLeftConstraint->setLimit(4,0,0);
m_data->m_ChainLeftConstraint->setLimit(5,0,0);
for(int a = 0; a < 6; ++a)
{
m_data->m_ChainLeftConstraint->setParam(BT_CONSTRAINT_STOP_ERP,limitConstraintStrength,a);
m_data->m_ChainLeftConstraint->setParam(BT_CONSTRAINT_STOP_CFM,0.0,a);
}
m_data->m_ChainLeftConstraint->setDbgDrawSize(btScalar(1.f));
m_dynamicsWorld->addConstraint(m_data->m_ChainLeftConstraint, true);
}
prevBody = body;
}
m_data->m_ChainRightBody = prevBody;
localA.setIdentity();localA.getOrigin() = btVector3(-bodycount,0,3);
localB.setIdentity();
localB.setOrigin(btVector3(0,0,0));
m_data->m_ChainRightConstraint = new CONSTRAINT_TYPE(*staticBody, *m_data->m_ChainRightBody, localA, localB EXTRAPARAMS);
m_data->m_ChainRightConstraint->setLimit(3,0,0);
m_data->m_ChainRightConstraint->setLimit(4,0,0);
m_data->m_ChainRightConstraint->setLimit(5,0,0);
for(int a = 0; a < 6; ++a)
{
m_data->m_ChainRightConstraint->setParam(BT_CONSTRAINT_STOP_ERP,limitConstraintStrength,a);
m_data->m_ChainRightConstraint->setParam(BT_CONSTRAINT_STOP_CFM,0.0,a);
}
}
#endif
m_guiHelper->autogenerateGraphicsObjects(m_dynamicsWorld);
}
void Dof6ConstraintTutorial::animate()
{
/////// servo motor: flip its target periodically
#ifdef USE_6DOF2
static float servoNextFrame = -1;
btScalar pos = m_data->m_ServoMotorConstraint->getRotationalLimitMotor(2)->m_currentPosition;
btScalar target = m_data->m_ServoMotorConstraint->getRotationalLimitMotor(2)->m_servoTarget;
if(servoNextFrame < 0)
{
m_data->m_ServoMotorConstraint->getRotationalLimitMotor(2)->m_servoTarget *= -1;
servoNextFrame = 3.0;
}
servoNextFrame -= m_data->mDt;
#endif
/////// constraint chain: pull the chain left and right periodically
static float chainNextFrame = -1;
static bool left = true;
if(chainNextFrame < 0)
{
if(!left)
{
m_data->m_ChainRightBody->setActivationState(ACTIVE_TAG);
m_dynamicsWorld->removeConstraint(m_data->m_ChainRightConstraint);
m_data->m_ChainLeftConstraint->setDbgDrawSize(btScalar(2.f));
m_dynamicsWorld->addConstraint(m_data->m_ChainLeftConstraint, true);
}
else
{
m_data->m_ChainLeftBody->setActivationState(ACTIVE_TAG);
m_dynamicsWorld->removeConstraint(m_data->m_ChainLeftConstraint);
m_data->m_ChainRightConstraint->setDbgDrawSize(btScalar(2.f));
m_dynamicsWorld->addConstraint(m_data->m_ChainRightConstraint, true);
}
chainNextFrame = 3.0;
left = !left;
}
chainNextFrame -= m_data->mDt;
/////// bouncing constraint: push the box periodically
m_data->m_BouncingTranslateBody->setActivationState(ACTIVE_TAG);
static float bounceNextFrame = -1;
if(bounceNextFrame < 0)
{
m_data->m_BouncingTranslateBody->applyCentralImpulse(btVector3(10,0,0));
bounceNextFrame = 3.0;
}
bounceNextFrame -= m_data->mDt;
m_data->frameID++;
}
void Dof6ConstraintTutorial::stepSimulation(float deltaTime)
{
//animate();
float time = m_data->m_timeSeriesCanvas->getCurrentTime();
float prevPos = m_data->m_TranslateSpringBody->getWorldTransform().getOrigin().x();
m_dynamicsWorld->stepSimulation(deltaTime);
float xPos = m_data->m_TranslateSpringBody->getWorldTransform().getOrigin().x();
m_data->m_timeSeriesCanvas->insertDataAtCurrentTime(xPos,0,true);
m_data->m_timeSeriesCanvas->insertDataAtCurrentTime(m_data->m_TranslateSpringBody->getLinearVelocity().x(),1,true);
if (deltaTime>0)
{
m_data->m_timeSeriesCanvas->insertDataAtCurrentTime((xPos-prevPos)/deltaTime,2,true);
}
prevPos = xPos;
m_data->m_timeSeriesCanvas->nextTick();
}
class CommonExampleInterface* Dof6ConstraintTutorialCreateFunc( CommonExampleOptions& options)
{
return new Dof6ConstraintTutorial(options.m_guiHelper);
}

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examples/Tutorial/Dof6ConstraintTutorial.h Normal file
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#ifndef GENERIC_6DOF_SPRING2_CONSTRAINT_TUTORIAL_H
#define GENERIC_6DOF_SPRING2_CONSTRAINT_TUTORIAL_H
class CommonExampleInterface* Dof6ConstraintTutorialCreateFunc(struct CommonExampleOptions& options);
#endif //GENERIC_6DOF_SPRING2_CONSTRAINT_TUTORIAL_H